Genetics reveal gemfish stocks and genetic drift

We are keen to give you a brief snapshot of results of the gemfish project.

As expected, the presence of two main stocks has been confirmed: one in the Great Australian Bight (GAB) and the other on the east coast of Australia. The amount of genetic difference between them is unusually large for a marine fish species.

There are at least two other, probably smaller stocks: one to the west of Bass Strait, the other on the west coast of Tasmania.

Immigrants from adjacent stocks can be detected using genotyping. The migrants may have a limited capacity to contribute to local spawning.

Comparisons between samples collected in 2014 (by this project) and 25 years ago (by a previous project) and among types of genetic markers suggests that gemfish stocks are experiencing pronounced genetic drift.

The results have significant implications for the sustainable exploitation of the resource.